Microstructure of Alloy Composite Coatings Reinforced by Ti(C,N) Particles through Laser Cladding Technology

A new in-situ synthesis method was employed to produce Fe-based alloy composite coating reinforced by Ti(C,N) particles on the surface of cast steel through CO₂ laser cladding technology.The phase compositions and the microstructure of the composite cladding layer were analyzed by X-ray diffraction (XRD),optical microscopy (OM) and transmission electron microscopy (TEM).The results show that the Ti(C_0.3N_0.7) particles are introduced by in-situ reaction between TiN particles and graphite powder added in advance during the laser cladding process,and most of the Ti(C,N) particles in the cladding layer are irregular shape with the size of 0.1~3.0 μm and dispersively distribute in the substrate;The substrate of laser cladding layer contains cell and fine dendrite crystals,and the Ti(C_0.3N_0.7) particles are tightly bonded to α-Fe (substrate) in the cladding layer with clean and smooth bonding interface.